Gas compressor

ABSTRACT

To provide a gas compressor in which fretting wear due to vibration of an oil separation filter is prevented to thereby achieve an improvement in durability. A gas compressor is provided with a press-fixing unit for press-fixing end portions of an oil separation filter. As the press-fixing means, for example, it is possible to adopt a construction including an abutment block portion against which the bottom end portion of the oil separation filter abuts, an outer peripheral block portion having a filter accommodating hole into which the oil separation filter is inserted, and a pressurizing plate put over the forward end portion of the oil separation filter and mounted and fixed to the outer peripheral block portion, wherein the forward end portion of the oil separation filter is provided so as to protrude from the filter accommodating hole on the surface of the outer peripheral block portion, and wherein the protruding forward end portion of the oil separation filter is pressurized and bent by the pressurizing plate to undergo elastic deformation.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a gas compressor for use in avehicle air conditioning system or the like and, more particularly, aimsto prevent fretting wear due to vibration of an oil separation filtercontained in an apparatus to thereby achieve an improvement indurability.

[0003] 2. Description of the Related Art

[0004] Conventionally, a gas compressor of this type has, as shown, forexample, in FIG. 7, a compression mechanism C in a compressor case 1,and this compression mechanism C sucks in low pressure refrigerant gasin a suction chamber 6 and compresses it before discharging it into adischarge chamber 5 as high pressure refrigerant gas. At this time, thehigh pressure refrigerant immediately after being discharged from thecompression mechanism C contains oil in the mist state filled for thepurpose, for example, of lubricating the sliding portion of thecompression mechanism portion C, and the oil ingredient in such highpressure refrigerant gas is separated by an oil separator 20 containedin the gas compressor.

[0005] The oil separator 20 has an oil separation filter 21 formed byrolling a wire net into a cylinder, and the oil ingredient in the highpressure refrigerant gas is separated when a high speed gas flow of highpressure refrigerant gas strikes upon the wire net constituting the oilseparation filter 21 or by the centrifugal force generated when highpressure refrigerant gas whirls inside the oil separation filter 21.

[0006] However, in the oil separator 20 of the conventional constructiondescribed above, in which a pulsating high speed gas flow incessantlystrikes upon the wire net constituting the oil separation filter 21, ifthe wire net is not supported and fixed in a satisfactory manner, avibration such as twist is generated in the entire wire net, with theresult that the constituent wire materials of the wire net (wires) rubeach other, and the wire net and the support member in contact therewithrub each other, resulting generation of so-called fretting wear of thewire net to damage the wire net.

[0007] The present invention has been made in view of the above problem.It is an object of the present invention to provide a gas compressor inwhich fretting wear due to vibration of the oil separation filter isprevented to thereby achieve an improvement in durability.

SUMMARY OF THE INVENTION

[0008] To achieve the above object, there is provided, in accordancewith the present invention, a gas compressor characterized by comprisinga compression mechanism portion which sucks in, compresses, anddischarges refrigerant gas, a discharge chamber for temporarily storingthe refrigerant gas discharged from the compression mechanism portion, adischarge passage which causes the compression mechanism portion tocommunicate with the discharge chamber and which guides the refrigerantgas discharged from the compression mechanism portion to the dischargechamber, an oil separation filter which is arranged in the dischargechamber and at the downstream end of the discharge passage and which isformed by shaping a lattice-like member into a cylindricalconfiguration, a press-fixing means for press-fixing the end portions ofthe oil separation filter, and an oil sump formed at the bottom of thedischarge chamber and adapted to store the oil separated by the oilseparation filter.

[0009] In the present invention, the oil separation filter as a whole isfirmly fixed by the press-fixing force when the press-fixing meanspress-fixes the end portions of the oil separation filter.

[0010] Here, as the press-fixing means, it is possible to adopt aconstruction comprising an abutment block portion against which thebottom end portion of the oil separation filter abuts, an outerperipheral block portion having a filter accommodating hole into whichthe oil separation filter is inserted, and a pressurizing plate put overthe forward end portion of the oil separation filter and mounted andfixed to the outer peripheral block portion, wherein the forward endportion of the oil separation filter is provided so as to protrude fromthe filter accommodating hole on the surface of the outer peripheralblock portion, and wherein the protruding forward end portion of the oilseparation filter is pressurized and bent by the pressurizing plate toundergo elastic deformation.

[0011] In this construction, the forward end portion of the oilseparation filter is pressurized and bent toward the abutment blockportion by the pressurizing plate to undergo elastic deformation, anddue to this elastic deformation of the oil separation filter, the oilseparation filter is strongly pressed against the pressurizing plate,the abutment block, and the outer peripheral block portion and fixedthereto.

[0012] It is possible to adopt a construction in which the forward endportion of the oil separation filter is previously bent in a fixeddirection by a bending amount smaller than a press-bending amount beforebeing press-bent by the pressurizing plate.

[0013] In this construction, the forward end portion of the oilseparation filter is press-bent by the pressurizing plate such that allthe portions thereof are directed in the same direction, so that theconstruction proves superior in operability in fixing the bendingdirection.

[0014] Further, it is desirable that the direction in which the forwardend portion of the oil separation filter is previously bent be towardthe inner side of the filter.

[0015] In this construction, the forward end portion of the oilseparation filter is press-bent by the pressurizing plate such that itis always directed to the inner side of the filter, so that there is nodanger of the bent forward end portion of the oil separation filterbeing caught between the pressurizing plate and the outer peripheralblock, making it possible to correctly mount and fix the pressurizingplate to the outer peripheral block portion.

[0016] It is possible to provide in the inner surface of the filteraccommodating hole a clearance groove which allows entrance of theforward end portion of the oil separation filter when it is press-bentto the filter outer side.

[0017] In this construction, for example, there is no directivity in thebending of the forward end portion of the oil separation filterpress-bent by the pressurizing plate, and even when the forward endportion of the oil separation filter is bent so as to be directed to thefilter outer side, this press-bent portion enters the clearance groove,so that there is no danger of the bent forward end portion of the oilseparation filter being caught between the pressurizing plate and theouter peripheral block, making it possible to correctly mount and fixthe pressurizing plate to the outer peripheral block portion.

[0018] The oil separation filter may, for example, be formed of alattice-like member, such as wire net or expanded metal; in particular,in the case of a wire net type oil separation filter, it is desirable tofuse by spot welding the regions where the constituent wire materials ofthe wire net (wires) intersect each other in order to prevent frettingwear as a result of the constituent wires of the wire net being rubbedagainst each other.

[0019] Further, the spot welding is performed in order to preventfretting wear mainly due to vibration between the constituent wirematerials of the wire net, and, from the viewpoint of the object of thisspot welding, it is desirable to increase the number of spot weldingpoints for the region where, for example, the high speed gas flow ofhigh pressure refrigerant gas first strikes directly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIGS. 1A and 1B are a sectional view of an embodiment of thepresent invention, of which FIG. 1A is a diagram showing the state priorto the fixation of the pressurizing plate by bolts, and FIG. 1B is adiagram showing the state after the fixation of the pressurizing plateby bolts.

[0021]FIGS. 2A and 2B are a perspective view of the oil separator ofFIGS. 1A and 1B, of which FIG. 2A is a diagram showing the state priorto the fixation of the pressurizing plate by bolts, and FIG. 2B is adiagram showing the state after the fixation of the pressurizing plateby bolts.

[0022]FIG. 3 is an explanatory diagram showing another embodiment of thepresent invention, showing how the oil separation filter forward endportion is previously bent.

[0023]FIG. 4 is an explanatory diagram showing another embodiment of thepresent invention, showing a clearance groove the oil separation filterforward end portion enters when bent.

[0024]FIG. 5 is an explanatory diagram showing another embodiment of thepresent invention, showing the spot-welded portions when the oilseparation filter is formed of a wire net.

[0025]FIGS. 6A and 6B are a perspective view of another embodiment ofthe present invention, of which FIG. 6A is a diagram showing the stateprior to the fixation of the pressurizing plate by caulking, and FIG. 6Bis a diagram showing the state after the fixation of the pressurizingplate by caulking.

[0026]FIG. 7 is an explanatory diagram showing the basic construction ofa gas compressor.

[0027]FIG. 8 is a sectional view taken along the line A-A of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0028] In the following, an embodiment of the gas compressor of thepresent invention will be described in detail with reference to FIGS. 1through 6. The components which are the same as those of theconventional construction will be described with reference to FIGS. 7and 8.

[0029] As shown in FIG. 7, the gas compressor of this embodiment has aconstruction in which a compression mechanism portion C is accommodatedin a one-end-open-type compressor case 1, and, between this compressionmechanism portion C and a front head 1-2 mounted to the open end of thecompressor case 1, there is defined a low pressure suction chamber 6(low pressure chamber); further, between the inner, closed end of thecompressor case 1 and the compression mechanism portions, there isformed a high pressure discharge chamber 5 (high pressure chamber).

[0030] The compression mechanism portion C has a cylinder 2 with asubstantially elliptical inner periphery, and side blocks 3 and 4 aremounted to the end surfaces of the cylinder 2; further, inside thecylinder 2, a rotor 7 is horizontally installed, and the rotor 7 issupported so as to be rotatable through the intermediation of a rotorshaft 8 at the axial center thereof, a bearing 9 of the front side block3, and a bearing (not shown) of the rear side block 4.

[0031] As shown in FIG. 8, in the rotor 7, there are radially formedfive slit-like vane grooves 11, and in each of these vane grooves 11, avane 12 is slidably arranged, each vane 12 being provided so as to beretractable from the outer peripheral surface of the rotor 7 toward theinner peripheral surface of the cylinder 2.

[0032] The inner space of the cylinder 2 is divided into a plurality ofsmall chambers by the inner wall of the cylinder 2, the inner surfacesof the side blocks 3 and 4, the outer peripheral surface of the rotor 7,and the side surfaces of the forward end portions of the vanes 12, andthe small chambers thus formed are compression chambers 13; thecompression chambers 13 rotate in the direction of the arrow A in FIG. 8to thereby continuously undergo variation in volume, and, through thisvariation in volume, they suck in and compress the refrigerant gas inthe suction chamber 6 and discharge it to the discharge chamber 5 side.

[0033] That is, when the volume of the compression chambers 13increases, the low pressure refrigerant gas in the suction chamber 6 issucked in by the compression chambers 13 through suction passages 14 ofthe cylinder 2, etc. and suction holes 15 of the side blocks 3 and 4.Then, when the volume of the compression chambers 13 starts to bereduced, the refrigerant gas in the compression chambers 13 iscompressed due to the volume reduction effect. Thereafter, when thevolume of the compression chambers 13 approaches minimum, reed valves 17a of cylinder discharge holes 16 provided near the ellipsoidshorter-diameter portion of the cylinder are opened by the pressure ofthe compressed high pressure refrigerant gas, whereby the high pressurerefrigerant gas in the compression chambers 13 passes through thecylinder discharge holes 16, discharge chambers 18 in the cylinder outerspace, and a high pressure gas passage 19 before it is discharged to thedischarge chamber 5 side and is temporarily stored in this dischargechamber 5.

[0034] That is, in the gas compressor of this embodiment, a series ofpassages consisting of the cylinder discharge holes 16, the dischargechambers 18 in the cylinder outer space, the high pressure gas passage19, etc. establish communication between the compression mechanismportion C and the discharge chamber 5, and constitutes a dischargepassage for guiding the refrigerant gas discharged from the compressionchambers 13 of the compression mechanism portion C to the dischargechamber 5; an oil separator 20 is provided at the downstream end of thisdischarge passage.

[0035] As shown in FIG. 1, the oil separator 20 is composed of an oilseparation filter 21, an abutment block portion 22, an outer peripheralblock portion 23, a pressurizing plate 25, etc.

[0036] The oil separation filter 21 is arranged at the downstream end ofsuch a discharge passage in the discharge chamber 5, and is of a wirenet type using as the lattice-like member a wire net, which is spirallyrolled into a cylinder.

[0037] Further, this oil separation filter 21 is attached to a filteraccommodating hole 26 of the outer peripheral block portion 23, and itsend portions are press-fixed by the abutment block portion 22 and thepressurizing plate 25.

[0038] That is, the outer peripheral block portion 23 has a filteraccommodating hole 26 whose diameter is somewhat larger than that of theoil separation filter 21 (See FIG. 2), and the oil separation filter 21is inserted into this filter accommodating hole 26 and secured therein;further, the abutment block portion 22 is formed such that the bottomend portion of the inserted oil separation filter 21 abuts it.

[0039] Further, in the case of this embodiment, the oil separationfilter 21 is inserted into the filter accommodating hole 26 of the outerperipheral block portion 23 as described above, and when the bottom endportion of this oil separation filter 21 abuts the abutment blockportion 22, the forward end portion 21 a of the oil separation filter 21protrudes from the filter accommodating hole 26 somewhat beyond thesurface 23 a of the outer peripheral block portion 23 as shown in FIG.1A.

[0040] That is, the entire longitudinal length L1 of the oil separationfilter 21 is somewhat larger than the depth (filter accommodation depth)L2 as measured from the filter abutment surface 22 a of the abutmentblock portion 22 against which the bottom portion of the oil separationfilter 21 abuts to the inlet 26 a of the filter accommodating hole 26.

[0041] Further, as shown in FIG. 1B, the forward end portion 21 a of theoil separation filter 21, which protrudes as described above, ispress-bent by the pressurizing plate 25 as the press-bending/crushingmargin as shown in FIG. 1B, whereby, between the pressurizing plate 25and the abutment block portion 22, the pressurizing plate 25 and theabutment block portion 22 press-fix the end portions of the oilseparation filter 21.

[0042] That is, as shown in FIG. 1A, the pressurizing plate 25 mountedand fixed to the outer peripheral block portion 23 by means of bolts25-1 is put over the oil separation filter forward end portion 21 a; dueto the fastening force when fastening the pressurizing plate 25 to theouter peripheral block portion 23 by means of the bolts 25-1, a forcepress-bending the oil separation filter forward end portion 21 a isgenerated in the pressurizing plate 25. Then, due to this press-bendingforce, the oil separation filter forward end portion 21 a is pressedagainst the abutment block portion 22 and undergoes elastic deformationand plastic deformation to be press-bent as shown in FIG. 1B. By theelastic force due to the elastic deformation of the elastic deformationout of the above elastic deformation and plastic deformation of the oilseparation filter 21, the oil separation filter 21 is clamped so as tobe strongly pressed against and fixed to the pressurizing plate 25; theabutment block portion 22, and the outer peripheral block portion 23.

[0043] As described above, this embodiment adopts an arrangement inwhich the oil separation filter 21 undergoes not only elasticdeformation but also plastic deformation. This is due to the fact thatan elastic deformation involving plastic deformation allows the elasticforce to be exerted to the utmost. Thus, by forming the oil separationfilter 21 of a material with high Young's modulus and appropriatelysetting the crushing margin of the oil separation filter 21, it is alsopossible to achieve an equivalent elastic force solely through elasticdeformation involving no plastic deformation.

[0044] The abutment block portion 22 and the outer peripheral blockportion 23 are provided integrally through the intermediation of a baseblock portion 24, and are mounted and fixed to the rear side blockconstituting the wall surface of the discharge chamber 5.

[0045] Further, provided in the base block portion 24 is a communicationpassage (not shown) establishing communicating connection between thehigh pressure gas passage 19 (See FIG. 7) and the filter accommodatinghole 26, and high pressure refrigerant gas is introduced from the highpressure gas passage 19 to the oil separation filter 21 side throughthis communication passage (not shown) . The high pressure refrigerantgas thus introduced strikes against the wire net constituting the oilseparation filter 21, and whirls circumferentially inside the oilseparation filter 21.

[0046] At this time, also in the gas compressor of this embodiment, aforce causing the oil separation filter 21 to vibrate is generated bythe high speed gas flow of pulsating high pressure refrigerant gas;since this oil separation filter 21 is strongly pressed against andfixed to the abutment block portion 22 and the outer peripheral blockportion 23 as a result of the above-described elastic deformation,vibration of the oil separation filter 21 is prevented. Thus, theproblem due to the vibration of this type of oil separation filter 21,that is, the so-called fretting wear of the wire net caused by theconstituent wire materials (wires) constituting the oil separationfilter 21 rubbing each other or the wire net and the support member incontact therewith rubbing each other, is substantially reduced, therebyimproving the durability of the gas compressor.

[0047] Also in the gas compressor of this embodiment, oil is containedas a mist in the high pressure refrigerant gas immediately after itsdischarge from the compression mechanism portion C; due to the strikingof the high pressure refrigerant gas against the oil separation filter21 and the centrifugal force generated by the whirling of the highpressure refrigerant gas inside the oil separation filter 21, the oilingredient in the high pressure refrigerant gas is separated, and dripsinto the oil sump 28 at the bottom of the discharge chamber 5 to bestored there.

[0048] While in the above embodiment a construction is adopted in whichthe oil separation filter forward end portion 21 a is press-bent by thepressurizing plate 25, not all the portions of the oil separation filterforward end portion 21 a are necessarily bent so as to be directed inthe same direction when the oil separation filter forward end portion 21a is press-bent. For example, it can happen that a part of the oilseparation filter forward end portion 21 a is bent so as to fall on thefilter outer side. In this case, the outwardly bent portion of the oilseparation filter forward end portion 21 a can stick out and get caughtbetween the pressurizing plate 25 and the outer peripheral block portion23, making it difficult to mount and fix the pressurizing plate 25 tothe outer peripheral block portion 23 correctly.

[0049] In order to prevent the oil separation filter forward end portion21 a from thus sticking out, it is desirable, as shown in FIG. 3, forthe oil separation filter forward end portion 21 a to be bent previouslyand positively in a fixed direction, more specifically, toward thefilter inner side, before being press-bent by the pressurizing plate 25.

[0050] When this construction is adopted, all the portions of the oilseparation filter forward end portion 21 a are press-bent in the samedirection in conformity with the direction of the previous bending, thatis, toward the filter inner side by the pressurizing plate 25, so that asuperior operability is achieved in fixing the bending direction, andthere is no danger of the bent oil separation filter forward end portion21 a sticking out and getting caught between the pressurizing plate 25and the outer peripheral block portion 23, whereby it is possible tocorrectly mount and fix the pressurizing plate 25 to the outerperipheral block portion 23.

[0051] In the above construction, the pre-bending amount of the oilseparation filter forward end portion 21 a is less than the amount bywhich the oil separation filter forward end portion 21 a is press-bentby the pressurizing plate 25 because if the latter is larger than that,the press-bending of the oil separation filter forward end portion 21 aby the pressurizing plate 25 is impossible, and the above effect of thispress-bending, that is, the effect of firmly fixing the oil separationfilter 21 through elastic deformation, cannot be obtained.

[0052] Further, regarding the means for preventing the oil separationfilter forward end portion 21 a from sticking out, it is also possibleto adopt a sticking-out preventing structure as shown in FIG. 4. In thesticking-out preventing mechanism shown in the drawing, a clearancegroove 27 is annularly formed in the inner peripheral surface of thefilter accommodating hole 26. In the case of this structure, when theoil separation filter forward end portion 21 a is press-bent on thefilter outer side, the press-bent portion enters this clearance groove27.

[0053] Thus, like the structure in which the oil separation filterforward end portion 21 a is bent previously and positively, thesticking-out preventing structure of FIG. 4 makes it possible toeffectively prevent the bent oil separation filter forward end portion21 a from sticking out and getting caught between the pressurizing plate25 and the outer peripheral block portion 23, making it possible tomount and fix the pressurizing plate 25 to the outer peripheral blockportion 23 correctly.

[0054] By adopting both the oil separation filter forward end portion 21a bending structure shown in FIG. 3 and the clearance groove 27 shown inFIG. 4, it is possible to more effectively prevent the oil separationfilter forward end portion 21 a from sticking out.

[0055] In the above-described embodiment, the wire net type oilseparation filter 21 is adopted; when using this wire net type oilseparation filter 21, it is desirable to perform spot welding for fusingconnection on the regions where the constituent wire materials (wires)of the wire net intersect each other, as shown in FIG. 5. This spotwelding is performed for the purpose of preventing fretting wear mainlydue to vibration between the constituent wire materials of the wire net.Thus, from the viewpoint of the purpose of the spot welding, it isdesirable to increase the number of spot welding points in the regionsespecially subject to large vibration, e.g., the region where the highspeed gas flow of high pressure refrigerant gas first strikes directly.

[0056] In the above-described embodiment the oil separation filterforward end portion 21 a is press-bent by the fastening force whenfastening the pressurizing plate 25 to the outer peripheral blockportion 23 by means of the bolts 25-1; instead, it is also possible, asshown in FIG. 6, to fix the pressurizing plates 25 to the filteraccommodating holes 26 of the outer peripheral block portion 23 bycaulking, and to press-bent the oil separation filter forward endportion 21 a by the caulking force.

[0057] Further, apart from the wire net, the lattice-like memberconstituting the oil separation filter 21 may also consist, for example,of expanded metal; in the case of expanded metal, a thin plate with finealternate slits is expanded into a lattice-like form like a wire net;the oil separation filter 21 may be formed by shaping this expandedmetal into a cylinder.

[0058] As described above, in the gas compressor of the presentinvention, there is provided a press-fixing means for press-fixing theend portions of the oil separation filter, and the entire oil separationfilter is firmly fixed by the press-fixing force when the press-fixingmeans press-fixes the end portions of the oil separation filter. Thus,it is possible to effectively prevent a phenomenon of the oil separationfilter being vibrated due to the high speed gas flow of the pulsatinghigh pressure refrigerant gas, and it is possible to substantiallymitigate the problem due to vibration of this type of oil separationfilter, e.g., fretting wear of the wire net constituting the oilseparation filter, making it possible, for example, to improve thedurability of the gas compressor.

What is claimed is:
 1. A gas compressor comprising: a compressionmechanism portion which sucks in, compresses, and discharges refrigerantgas; a discharge chamber for temporarily storing the refrigerant gasdischarged from the compression mechanism portion; a discharge passagewhich causes the compression mechanism portion to communicate with thedischarge chamber and which guides the refrigerant gas discharged fromthe compression mechanism portion to the discharge chamber, an oilseparation filter which is arranged in the discharge chamber and at adownstream end of the discharge passage and which is formed by shaping alattice-like member into a cylindrical configuration; a press-fixingmeans for press-fixing end portions of the oil separation filter; and anoil sump formed at a bottom of the discharge chamber and adapted tostore the oil separated by the oil separation filter.
 2. A gascompressor according to claim 1, wherein the press-fixing meanscomprises: an abutment block portion against which a bottom end portionof the oil separation filter abuts; an outer peripheral block portionhaving a filter accommodating hole into which the oil separation filteris inserted, and; a pressurizing plate put over a forward end portion ofthe oil separation filter and mounted and fixed to the outer peripheralblock portion; and that the forward end portion of the oil separationfilter is provided so as to protrude from the filter accommodating holeon the surface of the outer peripheral block portion, and the protrudingforward end portion of the oil separation filter is pressurized and bentby the pressurizing plate to undergo elastic deformation.
 3. A gascompressor according to claim 1, wherein the forward end portion of theoil separation filter is previously bent in a fixed direction by abending amount smaller than a press-bending amount before beingpress-bent by the pressurizing plate.
 4. A gas compressor according toclaim 2, wherein the direction in which the forward end portion of theoil separation filter is previously bent is toward the inner side of thefilter.
 5. A gas compressor according to claim 1, wherein there isprovided in the inner surface of the filter accommodating hole aclearance groove which allows entrance of the forward end portion of theoil separation filter when bent toward the outer side of the filter. 6.A gas compressor according to claim 1, wherein the oil separation filterconsists of a wire net.
 7. A gas compressor according to claim 1,wherein the oil separation filter consists of a wire net; and that spotwelding is performed for fusing connection on the regions where theconstituent wire materials of the wire net intersect each other.
 8. Agas compressor according to claim 7, wherein the spot welding isincreased in the number of points at the region of the entire oilseparation filter where the high speed gas flow of high pressurerefrigerant gas first strikes directly.
 9. A gas compressor according toclaim 1, wherein the oil separation filter is formed of expanded metal.